Process of making sulfuric acid and sulfur anhydrid.



P atent'ed May 20,1902 c KRAUS-S warm.- vuu .BEBNECK. PROCESS OF MAKING SULFURIC ACID AND SULFUR ANHYDBID.

(Application filed. Mar. 6, 1902.)

(No Model.)

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UNITED S AT PATENTQQEITICE' CONSTANTIN KRAUSS AND RUDOLPH MULLER VON BERNECK, OF

ON-THE-MAIN, GERMANY, ASSIGNORS TO FARBWERKE, voRMl MEISTER,

LUGIUS & BRI TNING, OF HCOHST-ON-TI-IE-MAIN, GERMANY, A OORPQRA- TION OF GERMANY.

PROCESS OF-MAKING SULFURIC ACID AND SULFUR ANHYDRID/ SPECIFICATION forming part of Letters Patent No. 700,512, dated May 20, mos.

Application filed naicileieoz. Serial Nd 96,921. (Nospecimens-l I To all whom it may concern. I

Ph. D., and RUDOLPH MiiLLFJRZVoN B RnEc chemist, citizens of the Empire'of Germany, 7 residing at Hochst-on-the-ll/lain,"' Germany, have invented certain newandusefullm:

provements in Processes of Making Sulfuric; Acid and Sulfur Anhydrid, of which the following is a specification. j I 10' I It is known that ferric oxid,vlike platinum, may be used as a catalytic agent or contact substance for effecting the combinationof sulfur dioxid and oxygen to form sulfurieanhy drid. For this purpose-{the gases from a drid and sulfuric acid or of the former aloneby bringing pyrites-burner gases or like mix ture of gases into contact with burnt pyrites or like oxid of iron, one result of which improvements is that the unoxidizedsulfur in the burnt pyrites is oxidized and separated. .a

' From our experiments appears thatwhen dry pyrites-burner gases are passed over burnt pyrites at a comparatively low temperature sulfur dioxid disappears from the gaseswithout formation of an equivalent ofsulfuric f anhydrid, being presumably} fixed by the x burnt pyrites. n

marked when the burnt; pyrites has been previously impregnated withferrous sulfate.

This phenomenon is more When the temperature offlthe burnt pyrites is raised, both the sulfuricanhydrid and sul- -40 fur dioxid in the gases passing away from the At still higher temperaapparatus increase.

vtu'res the burnt pyrites begins to act catalytically, and then, as we have .discovered, the action is notably enhancedifthe burnt yrites'has been previously impregnated with ferrous sulfate. Wehave also observed that the fixation of sulfur dioxid by the burnt ,py-

rites at the low temperature is better, and the oxidation of the unoxidized sulfur inthe v p bu r ntpyrites is better'if the gases to be com Be it known that We, CONSTANTINKRAUSS,"

bined contained a small quantityof moisture. Ourinvention consists in applying these ob+ servationsby exposing the burnt pyrites to pyrites-burner gases or other mixture of gases 1 containing sulfur dioxid-and oxygen, first at a comparatively low temperature-say about a 350 centigrade and then at highertemperaattaining some 550 I or instance, 1111611011? j 7 6e orotherwise obtained are directly passed tures, preferably finall to 650 centigrade. und'riedgases leaving'the furnace or burner through alchannel wherein burnt pyrites is made to meet the current of gas.

.with ferrous sulfate. In this manner the gases are gradually cooled to the said low 7 Theburnt pyrites is preferablysaturated previously I temperature, while the burnt pyrites'is gradually heated to the said high temperature, so

that there is an uninterrupted delivery of inder O,- which may have longitudinal inter Into the upper end of,

nal ribs or shelves.

this cylinderthe burnt pyrites, eitherin p0w-' der. or coarse lumps, previously saturated" I."

with ferrous sulfate, is fed from a hopper,"to

which it is raised by a suitable-conveyor. Thehot gases from a pyrites-burner K pass 1 into thejlower endof thecylinder, so that the a j descending material meets the ascending current of gradually-coolinggases until it drops 91 k from the lower'end of the cylinder. ,Atthe' upper and cooler part ofthe cylinder, whiclr i may here be externally cooled,'if'necessary,

sulfur dioxid is fixed by the burnt pyritesp In the nextvand hotter zone the ferrous sul fate in the material is decomposed and thev I sulfuric anhydrid'therefrom and from the sul- I I fur dioxid fixed, in the first zone is evolved I In the third and hottest zone catalysis may occur, the gases being for this purpose conducted through a suitable chamber K Our invention is not limited to this form of apparatus, as others may be adopted for the manufacture by this process.

Although burnt pyrites has been spoken of as the contact substance, other form of ferric oxid may be used.

Having now described our invention, What We claim is The herein-described process of making sulfuric acid and sulfur anhydrid with simultaneous combustion of the unoxidized sulfur still contained in the bu'rntpyritcs, which consists in bringing pyritcs-burner gases at a low temperature into contact with burnt pyrites containing ferrous sulfate, whereby sulfur dioxid is fixed by the burnt pyrites and in then applying a higher temperature the fixed sulfur dioxid being again separated as sulfuric anhydrid, substantially as set forth.

In testimony that We claim the foregoing as our invention we have signed our names in presence of two subscribing Witnesses.

CONSTANTIN KRAUSS. RUDOLPH MULLER VON BERNEUK. Witnesses:

ALFRED BRISBOIS, BnRNI-IARD LEYDECKER. 

